Browsing by Author "Maicykutty P Mathew"

Now showing 1 - 11 of 11

Bio-efficacy and molecular charaterization of the native isolates of Bacillus thuringiensis Berliner
(Department of Agricultural Entomology, College of Horticulture, Vellanikkara, 2008) Jyothi Sara Jacob; Maicykutty P Mathew
Bacillus thuringiensis Berliner shortly known as B.t., is a gram-positive, spore forming bacterium that produces proteinaceous crystal containing insecticidal toxins. The host range of B.t. has expanded considerably due to extensive screening programmes. By virtue of its lack of toxicity towards other species of animals and human beings, B.t. has emerged as a safe candidate in the IPM programmes of various agroecosystems. Frequent exposure to one type of B. thuringiensis toxins can develop resistance in insects. Isolation of novel strains is important to overcome the onset of insect resistance. The present study on “Bio-efficacy and molecular characterization of native isolates of Bacillus thuringiensis Berliner” was conducted at the Department of Agricultural Entomology and CPBMB, College of Horticulture, Vellanikkara during the period from 2006 to 2008 with an objective to study the pathogenicity of 20 B. thuringiensis isolates collected from the Western Ghats of Kerala, one of the well known hot spots of biodiversity. The tobacco caterpillar, Spodoptera litura Fb. which was used as the test insect was reared in semi-synthetic diet (Ballal, 2004) and also in natural diet on castor leaves. The preliminary screening was performed for lepidopteran specificity with the ideal dose of 1 x 109 spores per ml showed that three isolates were toxic to S. litura. The per cent mortality caused by the lepidopteran effective isolates, namely, KAU-11, KAU-51, KAU-166 and the reference strain, HD-1 were 76.7 per cent, 80.0 per cent, 86.7 percent, 96.7 per cent respectively. A standardized bioassay was carried out with five different concentrations of all the selected isolates namely, KAU-11, collected from Thusharagiri (Calicut Dt.), KAU-51 from Kolahalamedu (Idukki Dt.), KAU-166 from Nelliyampathi (Palakkad Dt.) and the reference standard HD-1 (B. thuringiensis subsp. kurstaki). The mortality ranged from 63.3 to 100.0 per cent in various isolates and there was no significant difference between isolates. This indicated the equal effectiveness of the native isolates with the standard strain, HD-1. The LC50 value for the isolates was calculated by Finney’s Method of Probit Analysis. The lowest LC50 was obtained in KAU-51, with 6.3095 x 104 spores per ml and highest in KAU-11, with 1.2589 x 106 spores per ml. The lethal time to cause 50 per cent mortality (LT50) ranged from 44.4 h. to 96.0 h. in different isolates. The lowest LT50 was recorded in HD-1, which shows the ability of the standard to cause mortality slightly earlier compared to other isolates. The molecular characterization of the selected isolates was performed with RAPD-PCR technique. RAPD-PCR is a simple and rapid method for determining genetic diversity in various organisms and is a means of creating a biochemical finger print of an organism. Out of the 20 primers screened, 10 primers which produced more than five bands were selected for RAPD analysis. The RAPD data was used to generate a similarity matrix using the NTSyS programme. Clustering was done and dendrogram was drawn using Unweighted Pair Group Method of Arithematic Averages (UPGMA). The results showed that high variability exists between the selected isolates. Further studies are required to identify the subspecies of the efficient B.t. isolates to evaluate the field effectiveness against S. litura and other major lepidopteran pests for its utilization in pest management programmes. More primers need to be screened to study the genetic diversity of the isolates.
Biology and management of root mealybug on banana cultivars
(Department of Agricultural Entomology, College of Horticulture, Vellanikkara, 2007) Smitha, M S; Maicykutty P Mathew
Bionomics and host range of american serpentine leaf miner liriomyza trifolii (burgess) (agromyzidae :diptera)
(Department of Agricultural Entomology, College of Horticulture,Vellanikkara, 2003) Smitha, M K; Maicykutty P Mathew
The present investigation on the "Bionomics and host range of American serpentine leaf miner, Liriomyza trifolii (Bugcss) (Agrornyzidae: Diptera)" was undertaken in the Department or Entomology, College of Horticulture, Vellanikkara during 2001-2002. Field surveys and laboratory studies were carried out with the objective of studying the biology, host range, natural enemies and seasonal incidence of L. trifolii. The biology of L. trifolii was studied by releasing a pair of one day old adult l1ies 10 the rearing cages where cow pea seedlings were kept as host plants and honey as a food source. The female Ily inserted its eggs in the tubular punctures made on the leaves with its pointed ovipositor. The oval, translucent, milky white eggs hatched in about 2.08 days. The larvae mined the upper leaf surface and produced characteristic serpentine mines. There were four larval instars having a total duration of 3.4days. Alter the larvae attained full size or 2.35 mm length and (),(i4 mill width it made a semicircular cut at the broad end of the leaf mine. Through this cut larva came out of the mine and fall down to the soil for pupation. Inside the soil the larva turned to golden yellow coloured pupa. Female pupa was larger compared to male pupa. Adult emergence took place after 7.9 days. The adults had a longevity varying form 4.5days for mall's and 7.4 days for females where as they were feed with 2 per cent honey solution. Adult females were larger than the males and had black pointed spot on the lower sick of last abdominal segment. The fecundity of female varied from 14.6 eggs per day per female. The adult female laid about 48-5'0 eggs in its life time. The ratio or oviposition or feeding puncture was I: R.QC) to 1: 9.3. The total life cycle from eggs to adult took 13.3 days. The host range was studied by conducting surveys at regular intervals. 48 host plants belonging to 13 plant families were reported as host plants of this pest. It is a highly polyphagous insect and majority or the host plants belonged to families of Cornpositac and Cucubitaccae. The intensity of infestation of 1.. trifolli on various crops were calculated by counting the number of larval mines per leaf on the upper, middle and lower leaves of the plants. The attack of L. trifolt! was more on the lower leaves compared to middle and top leaves. Cowpea was found to be the most preferred host plant of L. trifolii followed by ash gourd, ridge gourd, tomato, pumpkin and cucumber. Among the ornamentals dahlia and marigold were severely damaged by this leaf miner. The intensity of infestation per unit area was maximum on tomato (l.74 mines per cm2) followed by cowpea (1.14 mines per cnr'). The number of mines per unit area was lowest for pumpkin (0.33 mines per ern"). In the studies on the seasonal incidence of L. trifolii two peak periods of infestation was observed, one during November and the second during January. The leaf miner population was observed to be highest from second fortnight of November to second fortnight of April. A significant positive correlation of larval population with wind velocity, sunshine hours and evaporation rate was observed. Relative humidity and total rainfall had negative correlation with infestation of L. trifolii. Parasitisation of L. trifolii by larval and pupal parasitoids were observed and the percentage of parasitoids were observed and the percentage of parasitism was maximum during December, J,U1uaIY and February months coinciding with the peak infestation periods. These natural enemies can be effectively utilized for the management of L. trifolii.
Biopesticides for integrated pest management in bitter gourd (Momordica charantia L.)
(Department of Agricultural Entomology, College of Horticulture, Vellanikkara, 2000) Sunil Dutt, M; Maicykutty P Mathew
A field study was undertaken at the College of Horticulture, Vellanikkara during 1998-99 to compare the efficacy of two chemical insecticides viz., acephate, carbofuran, two biopesticides based on B. thuringiensis and B. bassiana and their combinations against the major pests of bitter gourd. Carbofuran was applied as granules at seeding, while the other treatments were applied as spray at fortnightly intervals from 35 DAS. It was observed from the study that application of acephate at 0.1 per cent was the most effective insecticide against sap feeders viz., leaf hopper and aphids. The combined application of B. thuringiensis or B. bassiana with acephate 0.05 per cent was also found effective. In controlling hadda beetle also, acephate at 0.1 per cent gave consistently good results. Gallfly infestation was minimum in acephate 0.1 per cent treated plots followed by B. thuringiensis + acephate 0.05 per cent sprayed plots. In the case offruitfly, B. bassiana + acephate 0.05 per cent registered the lowest infestation. The borer infestation was less in B. thuringiensis + acephate 0.05 per cent sprayed plots. This treatment also recorded the highest marketable yield (7573 kg ha") with the highest net profit of Rs. 25,344 ha-I and benefit cost ratio of 3.71 : 1. Studies on the residues of carbofuran by high performance liquid chromatography revealed that application of carbofuran either at 0.6 or 1.2 kg a.i.ha' at seeding resulted in no detectable terminal residue in bitter gourd fruits.
Biotic agents for the management of American serpentine leaf miner, Liriomyza trifolii(Burgess) (Diptera:Agromyzidae)
(Department of agricultural entomology, College of horticulture, Vellanikkara, 2014) Jyothi Sara Jacob; Maicykutty P Mathew
A study on “Biotic agents for the management of American serpentine leaf miner, Liriomyza trifolii (Burgess) (Diptera: Agromyzidae)” was carried out at the Department of Agricultural Entomology, College of Horticulture, K.A.U., Vellanikkara during 2011-2013 with the objectives of collection and identification of indigenous natural enemies and to assess the pathogenicity of the entomopathogens to explore the feasibility of utilizing them for its management. Surveys were conducted in the vegetable fields for the collection and identification of natural enemies associated with L. trifolii in three districts, namely, Thrissur, Ernakulam and Kottayam from January to March, 2011. The surveys revealed the occurrence of nine species of hymenopteran parasitoids. The per cent parasitism varied from 10.96 to 58.99 per cent among the crops surveyed. Three species of eulophids, namely, Cirrospilus acadius Narendran, C. brevicorpus Shafee & Rizvi and Aprostocetus sp. as well as the braconid, Toxares sp. are new reports for India. Among the parasitoids, Closterocerus spp. were the dominant group followed by Chrysonotomyia sp. All parasitoids were solitary, larval endoparasitoids except Toxares sp. which was larval-pupal in nature. One species each of small ants (Formicidae) and a dipteran fly (Dolichopodidae) were observed as predators on L. trifolii. In the study, no entomopathogens were observed from L. trifolii. Considering the level of pesticide consumption in vegetable crops that undermine the potential of insect parasitoids and also that no entomopathogens could be observed during the survey, it was decided to evaluate entomopathogenic nematodes (EPNs) as biocontrol agents against L. trifolii. Isolation of EPNs from 72 soil samples from Thrissur, Ernakulam and Kottayam districts yielded four isolates of Steinernema carpocapsae. Bioefficacy studies carried out on these four isolates along with Steinernema bicornutum and Heterorhabditis indica showed that S. carpocapsae Isolate - 1 had the lowest LC 50 , LC 90 and LT values indicating their higher effectiveness against the maggots of the pest. 50 Pot culture study conducted to compare the potential of S. carpocapsae Isolate - 1 with other treatments showed that azadirachtin 1 EC at 0.005% was the most effective causing 84.51 per cent mortality to the maggots of L. trifolii. This was followed by the foliar application of H. indica at 32 infective juveniles (IJs)/ maggot which caused 18.98 per cent mortality. Application of Beauveria bassiana at 1×10 7 spores/ ml was not effective. In the field evaluation, fipronil 5 SC at 0.002% was found to be the most effective treatment for controlling L. trifolii followed by azadirachtin 1 EC at 0.005%. Compatibility of the IJs of the S. carpocapsae Isolate - 1, S. bicornutum and H. indica was studied with ten commonly used insecticides in the laboratory by direct exposure method. Chlorantraniliprole 18.5 SC at 0.005% was found to be the most compatible insecticide with S. carpocapsae isolate - 1 causing only 0.17 per cent mortality to IJs at 72 hours after treatment (HAT). Quinalphos 25 EC at 0.05% and chlorpyriphos20 EC at 0.05% were highly incompatible, causing 96.17 and 92.87 per cent mortality of the nematodes. Dimethoate 30 EC at 0.04% was the most compatible insecticide with S. bicornutum and caused only 0.60 per cent mortality at 72 HAT and was followed by azadirachtin 1 EC at 0.005% with 0.78 per cent mortality to the IJs. Quinalphos 25 EC at 0.05% caused 99.93 per cent mortality at 72 HAT. Heterorhabditis indica was compatible with all insecticides except quinalphos 25 EC at 0.05% which was moderately toxic resulting in 39.6 per cent mortality. The virulence, pathogenicity and multiplication of the survived IJs were not affected by the insecticide treatments. Parasitoids and EPNs were observed as potential candidates for the management of L. trifolii. Hence future studies on the bio-ecology and mass production of dominant parasitoids and standardization of methods to improve the efficacy of EPNs are suggested for the successful control of L. trifolii in polyhouses as well as in the field.
Diversity of leafhopper fauna in rice and vegetable ecosystems
(Department of Agricultural Entomology,College of Horticulture, Vellanikkara, 2016) Nesmi Abdul Khader, T K; Maicykutty P Mathew
Leafhoppers are one of the important groups of insect pests on agricultural crops. Vegetables and rice crop are subjected to infestation by a number of leafhopper species, leading to heavy economic loss. These leafhoppers suck sap from crops and inject toxic saliva into plant tissues resulting in hopper burn symptoms. They also cause damage when they oviposit into plant tissues. Some species act as vectors of plant pathogens viz., viruses, phytoplasmas, spiroplasmas and bacteria Eg. rice green leafhoppers. Nielson (1985) reported 151 species of leafhoppers as vectors of plant diseases and nearly 70 per cent of insect species transmitting plant disease agents are leafhoppers. The present study on “Diversity of leafhopper fauna associated with rice and vegetable ecosystems” was undertaken at Department of Agricultural Entomology, College of Horticulture, Vellanikkara during 2014-16 with the objectives to document the diversity of leafhoppers in rice and vegetable ecosystems in Thrissur district and to develop a dichotomous taxonomic key for their identification.
Eco - friendly management strategies against pod borer complex of cowpea vigna unguiculata var.sesquiedalis (L) verdcourt
(Department of Agricultural Entomology, College of Horticulture, Vellanikkara, 2013) Subhasree, S; Maicykutty P Mathew
Heliothis armigera, a new pest of bittergourd
(Kerala Agricultural University, 1996) Maicykutty P Mathew; Sheela Paul, T; Ramachandran Nair, S; Madhu, S
Hirsutella Thompson II var. Synnematosa Samson, Mccoy & O'donnell on coconut mite aceria (Eriophyes) guerreronis (Keifer) - a new report from India
(Kerala Agricultural University, 1999) Pathummal Beevi, S; Beena, S; Sukumara Varma, A; Lyla, K R; Maicykutty P Mathew; Nadarajan, L
IPM strategy in bittergourd using new generation insectisides and botanicals
(Department of Agricultural Entomology, College of Horticulture, Vellanikkara, 2005) Malarvizhi, G; Maicykutty P Mathew
The investigation on the “IPM strategy in bittergourd using new generation insecticides and botanicals” were carried out in the field as well as in the laboratory of Department of Entomology, College of Horticulture, Vellanikkara during October 2003 to February 2004. The present investigation revealed that profenofos gave high mortality to epilachna beetles, NSKE and spinosad were safe to honey bees and spinosad alone was found to be safe to predatory coccinellids under laboratory conditions. Under field conditions ethofenprox was found as the most effective insecticide against leafhoppers, profenofos against epilachna beetle and all chemical treatments and NSKE against leaf miner infestation. Spinosad, citronella oil, NSKE, fipronil and deltafos recorded lower pumpkin caterpillar infestation. NSKE, fipronil, deltafos and spinosad consistently effective in reducing the gall fly infestation. Citronella oil, NSKE and deltafos had registered the lower fruit fly infestation. The fruit borer infestation was less in the plots treated with spinosad, citronella oil and woodash. All botanicals and woodash harboured spider predators and spinosad was comparatively safe to spiders. Citronella oil and NSKE recorded higher coccinellid predators
Typhlocybine leafhopper on bittergourd
(Kerala Agricultural University, 1996) Maicykutty P Mathew